RESUMEN
Our prior work identified the mammalian target of rapamycin complex 2 (mTORC2) as a key regulator of bladder cancer cell migration and invasion, although upstream growth factor mediators of this pathway in bladder cancer have not been well delineated. We tested whether transforming growth factor (TGF)-ß, which can function as a promotility factor in bladder cancer cells, could regulate mTORC2-dependent bladder cancer cell motility and invasion. In human bladder cancers, the highest levels of phosphorylated SMAD2, a TGF-ß signaling intermediate, were present in high-grade invasive bladder cancers and associated with more frequent recurrence and decreased disease-specific survival. Increased expression of TGF-ß isoforms, receptors, and signaling components was detected in invasive high-grade bladder cancer cells that expressed Vimentin and lacked E-cadherin. Application of TGF-ß induced phosphorylation of the Ser473 residue of AKT, a selective target of mTORC2, in a SMAD2- and SMAD4-independent manner and increased bladder cancer cell migration in a modified scratch wound assay and invasion through Matrigel. Inhibition of TGF-ß receptor I using SB431542 ablated TGF-ß-induced migration and invasion. A similar effect was seen when Rictor, a key mTORC2 component, was selectively silenced. Our results suggest that TGF-ß can induce bladder cancer cell invasion via mTORC2 signaling, which may be applicable in most bladder cancers.
Asunto(s)
Complejos Multiproteicos/fisiología , Serina-Treonina Quinasas TOR/fisiología , Factor de Crecimiento Transformador beta/fisiología , Neoplasias de la Vejiga Urinaria/patología , Benzamidas/farmacología , Cadherinas/metabolismo , Movimiento Celular/fisiología , Dioxoles/farmacología , Humanos , Diana Mecanicista del Complejo 2 de la Rapamicina , Invasividad Neoplásica , Fosforilación/fisiología , Receptores de Factores de Crecimiento Transformadores beta/antagonistas & inhibidores , Transducción de Señal/fisiología , Proteína Smad2/metabolismo , Proteína Smad4/metabolismo , Células Tumorales Cultivadas , Regulación hacia Arriba/fisiología , Neoplasias de la Vejiga Urinaria/fisiopatología , Vimentina/metabolismoRESUMEN
PURPOSE: Men with chronic prostatitis/chronic pelvic pain syndrome have higher self-reported rates of cardiac disease than controls. Peripheral arterial tone abnormalities correlate with cardiac disease and mortality. We studied vascular dysfunction in men with chronic prostatitis/chronic pelvic pain syndrome and controls. MATERIALS AND METHODS: A total of 21 men with chronic prostatitis/chronic pelvic pain syndrome and 14 asymptomatic controls were tested with an Endo-PAT®2000 machine which assessed the augmentation index, a measure of arterial stiffness, and reactive hyperemia index, a measure of endothelial vasodilation. Symptoms were measured with the National Institutes of Health Chronic Prostatitis Symptom Index and patient phenotype was characterized by the UPOINT (Urinary, Psychosocial, Organ Specific, Infection, Neurologic/Systemic, Tenderness of Skeletal Muscles) system. Statistical significance was set at p<0.05. RESULTS: Age was similar in the chronic prostatitis/chronic pelvic pain syndrome group (range 22 to 63 years, median 40) and controls (range 19 to 57, median 40). Patients had median symptom duration of 24 months (range 3 to 440), a mean Chronic Prostatitis Symptom Index score of 24.7±5.1 and mean UPOINT domains of 2.9±1.1 (range 1 to 5). The augmentation index was significantly higher (greater arterial stiffness) in patients with chronic pelvic pain syndrome vs controls (5.0%±2.3 vs -6.0%±3.0, p=0.006). The reactive hyperemia index was significantly lower (more endothelial dysfunction) in patients with chronic pelvic pain syndrome (1.76±1.2 vs 2.21±1.7, p=0.03). There was no correlation between symptom duration, severity or phenotype (number or type of UPOINT domains) and reactive hyperemia index or augmentation index. CONCLUSIONS: Men with chronic prostatitis/chronic pelvic pain syndrome have evidence of increased arterial stiffness and vascular endothelial dysfunction. This is the first mechanistic correlation found that links the higher incidence of self-reported cardiac disease in these patients. Noninvasive Endo-PAT testing may allow stratification of cases of chronic prostatitis/chronic pelvic pain syndrome by vascular dysfunction, which may require specific treatment or at least further assessment of cardiac risk.